JP2001012814A - Cooler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for supplementing refrigerant by confining the temperature of refrigerant liquid in a refrigerant container within a specified temperature band regardless of fluctuation in the atmospheric temperature over four seasons thereby suppressing fluctuation of pressure in the refrigerant container. SOLUTION: In a cooler 50 for cooling a shield plate 103 covering an object 107 to be cooled, e.g. a superconducting magnet, or a container 112 thereof, r.p.m. of a refrigerating machine 51 is controlled depending on the state of gas in a liquid reservoir 53 provided with a condenser 52 for refrigerant constituted of the low temperature section of the refrigerating machine 51.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for cooling a cooled object such as a superconducting magnet or a shield plate covering a container containing the cooled object. Such a superconducting magnet device can be used for a magnetic levitation vehicle, MRI, or the like.

[0002]

2. Description of the Related Art A body to be cooled such as a superconducting magnet is stored in a container containing liquid helium and cooled to about 4.5K in order to maintain a superconducting state. This container is vacuum-insulated, but heat enters from outside due to radiation and conduction.
Approximately 8
It is covered with a shield plate cooled to 0K.

As a cooling device for cooling the above-mentioned shield plate, a cooling device for a cryostat radiation shield plate (JP-A-3-17057) is disclosed. The cooling device will be described with reference to FIG. The refrigerant liquid 54 such as liquid nitrogen in the refrigerant container 53 of the refrigerant supply device 50
When the pressure is increased by 5 and flows into the conduit 101 in the cryostat 100 through the conduit 58, it absorbs the radiant heat entering the shield plate 103 from the vacuum chamber 105 and the conduction heat introduced through the support member 106 and evaporates itself. Thereby, the temperature of the shield plate 103 is kept almost close to the temperature of the frozen liquid 54.

As a result, heat does not directly enter the container 112 filled with the refrigerant 104 such as liquid helium from the vacuum tank 105. The refrigerant vapor flowing into the condenser 52 through the conduit 102 is cooled by the refrigerator 51 to be a liquid, and returns to the refrigerant container 53 again.

[0005]

In the above-described conventional cooling device, when the ambient air temperature increases, the heat entering the shield plate 103 as radiant heat and conduction heat from the vacuum chamber 105 increases. It is almost equal to the ambient temperature, the radiant heat is proportional to the difference between the fourth power of the vacuum chamber temperature and the fourth power of the shield plate, and the conduction heat is proportional to the difference between the vacuum chamber temperature and the shield plate temperature. When the temperature increases, there is a problem that heat (radiant heat and conductive heat) entering the shield plate 103 increases.

On the other hand, the refrigerating capacity at a predetermined temperature of the refrigerator is large in winter and small in summer, as is clear from the Carnot efficiency. For this reason, at a predetermined temperature equal to or lower than the shield, even if the refrigerating capacity of the refrigerator 51 and the cooling amount required for reliquefying the refrigerant vapor evaporated by the shield plate 103 are balanced in winter, the refrigerator 5 becomes
1, the refrigerating capacity at the predetermined temperature decreases, while the amount of cooling required to reliquefy the refrigerant vapor increases, so that the refrigerant vapor evaporated by the shield plate 103 cannot be completely reliquefied. .

For this reason, the pressure of the refrigerant container 53 increases steadily, so that the refrigerant vapor must be discharged from the refrigerant container 53 to the atmosphere, the refrigerant liquid such as liquid nitrogen decreases, and it becomes necessary to supply the refrigerant liquid. . Further, since the pressure of the refrigerant container 53 increases, the equilibrium temperature of the refrigerant increases, and the shield plate 10
3 also increases, so that the support material 108 is removed from the shield plate.
A vicious cycle occurs in which the amount of conduction heat that penetrates into the container 112 containing the superconducting magnet 107 through the passage increases.

Accordingly, the present inventor has proposed a cooling apparatus for cooling a shield such as a superconducting magnet or a container surrounding the cooled object, wherein the cooling medium for cooling the shield plate is provided. Focused on the technical idea of the present invention, in which the number of rotations of the refrigerator is controlled according to the state of the gas in the liquid reservoir in which the condensing part of the refrigerant, which is housed and constituted by the low-temperature part of the refrigerator, is provided, As a result of further research and development,
The present invention achieves the object of keeping the refrigerant liquid temperature in the refrigerant container within a predetermined temperature range, suppressing fluctuations in the pressure of the refrigerant container, and eliminating the need for replenishment of the refrigerant, irrespective of fluctuations in the atmospheric temperature in the four seasons. Reached.

That is, the present invention relates to a cooling apparatus for cooling a cooled object such as a superconducting magnet or a shield plate covering a container accommodating the cooled object. When the plate is cooled by the refrigerator, the temperature of the refrigerant liquid such as liquid nitrogen in the refrigerant container is kept within a predetermined temperature range, regardless of the fluctuation of the heat load of the shield plate due to the fluctuation of the atmospheric temperature in the four seasons. It is an object of the present invention to prevent the pressure from abnormally increasing and decreasing and to eliminate the need to supply the refrigerant.

[0010]

A cooling device according to the present invention (first invention according to claim 1) covers a body to be cooled such as a superconducting magnet or a container accommodating the body to be cooled. In the cooling device for cooling the shield plate, a refrigerant for cooling the shield plate is accommodated, and refrigeration is performed according to the state of gas in a liquid reservoir provided with a condensing portion for the refrigerant, which is constituted by a low-temperature portion of a refrigerator. It controls the rotation speed of the machine.

The cooling device according to the present invention (the second invention according to claim 2) is the cooling device according to the first invention, further comprising a pressure sensor for detecting a pressure of gas in the reservoir, and the detected pressure in the reservoir. The number of rotations of the refrigerator is controlled in accordance with the pressure of the gas.

The cooling device according to the present invention (the third invention according to claim 3) is the cooling device according to the second invention, further comprising a gas temperature sensor for detecting a temperature of gas in the liquid reservoir, and the detected liquid reservoir. The number of rotations of the refrigerator is controlled according to the temperature of the gas inside the refrigerator.

The cooling device of the present invention (fourth invention according to claim 4) is the cooling device according to the third invention, further comprising a shield plate temperature sensor for detecting a temperature of the shield plate, and a detected temperature of the shield plate. The number of rotations of the refrigerator is controlled in accordance with.

A cooling device according to the present invention (fifth invention according to claim 5) is the cooling device according to the fourth invention, further comprising a liquid temperature sensor for detecting a liquid temperature in the liquid reservoir, The number of revolutions of the refrigerator is controlled in accordance with the liquid temperature of the refrigerator.

The cooling device according to the present invention (the sixth invention according to claim 6) is the cooling device according to the fifth invention, further comprising a condenser temperature sensor for detecting a temperature of a condenser of the refrigerator. The number of rotations of the refrigerator is controlled in accordance with the temperature of the condenser of the refrigerator.

The cooling device according to the present invention (the seventh invention according to claim 7) is the cooling device according to the sixth invention, further comprising a vacuum chamber temperature sensor for detecting a temperature of a vacuum chamber containing the container. The number of rotations of the refrigerator is controlled according to the temperature of the vacuum chamber.

The cooling device according to the present invention (the eighth invention according to claim 8) is the cooling device according to the seventh invention, further comprising an atmospheric temperature sensor for detecting an ambient temperature around the vacuum chamber, and the detected vacuum chamber. The number of rotations of the refrigerator is controlled according to the ambient air temperature around the refrigerator.

A cooling device according to the present invention (a ninth aspect of the present invention) comprises: a cooled object or a container accommodating the cooled object;
A shield plate that covers the object to be cooled or the container, a pipe through which a refrigerant that cools the shield plate flows, and a cryostat including a vacuum tank that stores the object to be cooled or the container, the shield plate, and the pipe. A liquid reservoir containing the refrigerant, a pump for sending the refrigerant from the liquid reservoir, a pipe through which the refrigerant sent from the pump flows, and the liquid reservoir;
The pump, a shield plate cooling device including a vacuum chamber that stores the pipe, and a low-temperature device including a pipe that connects the cryostat and the shield plate cooler, wherein the liquid reservoir includes a low-temperature part of a refrigerator. A condenser for the refrigerant is provided, the pressure of the liquid reservoir, the liquid temperature of the liquid reservoir, the gas temperature of the liquid reservoir, the wall temperature of the liquid reservoir, the temperature of the pipe, the temperature of the shield plate, and the temperature of the refrigerator. At least one sensor output is detected among the temperature of the condenser, the temperature of the vacuum chamber, and the ambient temperature around the vacuum chamber, and the number of rotations of the refrigerator is controlled according to the detected sensor output. .

The present invention (the tenth aspect of the present invention)
In the cooling device of the ninth aspect, the liquid reservoir and the condensing portion of the refrigerator are connected by a telescopic member.

The present invention (the eleventh invention according to claim 11)
The cooling device according to the ninth aspect, wherein the liquid reservoir is provided with a condensing portion for the refrigerant constituted by a low-temperature portion of the refrigerator, and a telescopic member is provided between the normal-temperature portion of the refrigerator and the vacuum tank. It is a combination.

The present invention (a twelfth aspect of the present invention)
In the cooling device of the ninth aspect, in the ninth aspect, the refrigerator is a regenerative refrigerator, and a condenser is provided in both a low-temperature part of the regenerator and a low-temperature part of the expansion part of the refrigerator.

[0022]

The cooling device according to the first aspect of the present invention has the above-described structure, in which a refrigerant for cooling the shield plate is accommodated, and the liquid condensing portion provided with a low-temperature portion of the refrigerator is provided. Since the number of rotations of the refrigerator is controlled according to the state of the gas in the reservoir, the refrigerant liquid temperature in the refrigerant container is kept within a predetermined temperature range, regardless of the fluctuation of the atmospheric temperature in the four seasons,
This has the effect of suppressing fluctuations in the pressure of the refrigerant container and making it unnecessary to supply the refrigerant.

[0023] The cooling device of the second invention having the above-described structure includes:
In the first invention, since the rotation speed of the refrigerator is controlled in accordance with the pressure of the gas in the liquid reservoir detected by the pressure sensor, control of the refrigeration capacity in accordance with the pressure of the gas in the liquid reservoir is performed. This has the effect of making it possible.

[0024] The cooling device of the third invention having the above-described structure includes:
In the second invention, since the number of rotations of the refrigerator is controlled according to the temperature of the gas in the reservoir detected by the gas temperature sensor, the refrigeration capacity is controlled according to the temperature of the gas in the reservoir. This has the effect of enabling

[0025] The cooling device of the fourth invention having the above-described structure includes:
In the third aspect, since the rotation speed of the refrigerator is controlled in accordance with the temperature of the shield plate detected by the shield plate temperature sensor, the refrigeration capacity in accordance with the directly detected heat load on the shield plate. The effect of enabling the control of is achieved.

The cooling device according to the fifth invention having the above-described structure,
In the fourth aspect, since the rotation speed of the refrigerator is controlled in accordance with the liquid temperature in the liquid reservoir detected by the liquid temperature sensor, the refrigeration capacity can be controlled in accordance with the liquid temperature in the liquid reservoir. This has the effect of

[0027] The cooling device of the sixth invention having the above structure is
In the fifth aspect, since the rotation speed of the refrigerator is controlled according to the temperature of the condenser of the refrigerator detected by the condenser temperature sensor, the refrigerating capacity of the refrigerator according to the temperature of the condenser of the refrigerator is controlled. This has the effect of enabling control.

The cooling device according to the seventh aspect of the present invention having the above structure,
In the sixth aspect, since the rotation speed of the refrigerator is controlled according to the temperature of the vacuum chamber detected by the vacuum chamber temperature sensor, it is possible to control the refrigeration capacity according to the temperature of the vacuum chamber. It works.

[0029] The cooling device of the eighth invention having the above-described structure,
In the seventh aspect, since the rotation speed of the refrigerator is controlled according to the ambient temperature around the vacuum chamber detected by the ambient temperature sensor, control of the refrigeration capacity according to the ambient temperature around the vacuum chamber is performed. This has the effect of enabling

The cooling device according to a ninth aspect of the present invention having the above structure,
The pressure of the liquid reservoir provided with the refrigerant condensing part constituted by the low temperature part of the refrigerator, the liquid temperature of the liquid reservoir, the gas temperature of the liquid reservoir, the wall temperature of the liquid reservoir, and the temperature of the pipe. ,
At least one sensor output among the temperature of the shield plate, the temperature of the condensing part of the refrigerator, the temperature of the vacuum chamber, and the atmospheric temperature around the vacuum chamber is detected, and the refrigeration is performed in accordance with the detected sensor output. Since the number of rotations of the air conditioner is controlled, refrigeration capacity can be controlled in accordance with the heat load on the shield plate. Within the width, there is an effect that the fluctuation of the pressure of the refrigerant container is suppressed and the supply of the refrigerant is not required.

In the cooling apparatus according to a tenth aspect of the present invention, the liquid reservoir and the condenser of the refrigerator are connected by a telescopic member in the ninth aspect of the invention. Thus, it is possible to avoid breakage due to heat shrinkage caused by the above, and it is possible to stably operate the vehicle.

In the cooling apparatus according to an eleventh aspect of the present invention, in the ninth aspect, a condenser for condensing the refrigerant, which is constituted by a low-temperature part of the refrigerator, is provided in the liquid reservoir. Since the vacuum chamber and the vacuum chamber are connected by an expansion / contraction member, it is possible to avoid breakage due to heat shrinkage that occurs between the condensing section and the room temperature section of the refrigerator, and has an effect that the operation can be stably continued. .

In the cooling apparatus according to a twelfth aspect of the present invention, in the ninth aspect, the refrigerating machine is a regenerative refrigerating machine, and the refrigerating machine is condensed in both the low temperature part of the regenerator and the low temperature part of the expansion part. Since the heat exchange area of the condensing part can be increased by providing the part, it is possible to easily control the temperature of the refrigerant liquid such as liquid nitrogen within a predetermined temperature range.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings.

(First Embodiment) As shown in FIG. 1, a cooling device according to a first embodiment of the present invention is a cooling device 1 such as a superconducting magnet.
07 or a cooling device 5 for cooling the shield plate 103 covering the periphery of the container 112 containing the object to be cooled.
0, a refrigerant for cooling the shield plate 103 is accommodated therein, and the refrigerator 51 is provided according to the state of gas in a liquid reservoir 53 provided with a condenser 52 of the refrigerant constituted by a low-temperature part of the refrigerator 51. Is to control the number of rotations.

The low-temperature device to which the cooling device of the first embodiment is applied includes a cooled object 107 or a container 112 containing the cooled object, a shield plate 103 covering the cooled object 107 or the container 112, A cryostat 1 composed of a pipe 101 through which a refrigerant for cooling the shield plate 103 flows, and the object to be cooled 107 or the container 112, the shield plate 103, and a vacuum chamber 105 for accommodating the pipe 101.
00, the reservoir 53 containing the refrigerant, and the reservoir 5
A pump 55 for sending refrigerant from the pump 3;
A pipe 58 through which the refrigerant sent from the reservoir 5 flows;
3. Vacuum tank 5 containing the pump 55 and the pipe 58
9 and a pipe 58 connecting the cryostat 100 and the shield plate cooling device 50.

The shield plate cooling device 50 includes the liquid reservoir 53 for storing a refrigerant liquid 54 such as liquid nitrogen, the refrigerator 51, the pump 55, the pipe 58, and the vacuum tank for storing these. It consists of 59.

The condenser 5 is provided at a low temperature part of the refrigerator 51.
The condenser 52 is airtightly engaged in the liquid reservoir 53. The normal temperature portion of the refrigerator 51 is similarly engaged with the vacuum chamber 59 while maintaining the airtightness.

The refrigerator 51 is, for example, a Stirling refrigerator, and is driven by an inverter 61 and a control device 62 for controlling the inverter 61.

The cryostat 100 includes a liquid helium container 112 containing a cooled object 107 such as a superconducting magnet, a shield plate 103 surrounding the liquid helium container 112, and a thermal contact with the shield plate 103. Piping 101 and a vacuum tank 105 for accommodating them.
The shield plate cooling device 50 is connected to a pipe 58 and a pipe 102.

In the first embodiment, the liquid reservoir 5
3, a liquid temperature sensor 202 for measuring the liquid temperature of the liquid reservoir 53, and a pressure sensor 201 for measuring the liquid temperature of the liquid reservoir 53.
A gas temperature sensor 203 for measuring the gas temperature of the reservoir, a wall temperature sensor 204 for measuring the wall temperature of the reservoir 53, a pipe temperature sensor 205 for measuring the temperatures of the pipe 58, the pipe 101 and the pipe 102, and the shield A shield plate temperature sensor 206 for measuring the temperature of the plate 103;
Condenser temperature sensor 2 for measuring the temperature of the condenser 52
07, a vacuum chamber temperature sensor 208 for measuring the wall temperature of the vacuum chamber 105 or the vacuum chamber 59, and an atmospheric temperature sensor 209 for measuring the ambient temperature around the vacuum chamber. The signal is used for controlling the control device 62.

In the first embodiment, the vacuum chamber 1
When the outside air temperature of 00, 50 changes, the vacuum chamber 10
The temperature of 0, 50 changes, the heat load of the shield plate 103 and the liquid reservoir 53 changes, and the state of the gas in the liquid reservoir 53 and the refrigerator 51 changes.

That is, when the state of the gas changes, the outlet temperature of the shield plate 103 changes (the pipe temperature sensor 2).
05) and the condensing section 52 of the refrigerator 51
When the temperature change (detected by the condenser temperature sensor 207) simultaneously changes and the pressure in the liquid reservoir 53 rises (detected by the pressure sensor 201), the gas temperature in the liquid reservoir 53 rises (the gas temperature sensor 203), the liquid temperature in the liquid reservoir 53 rises (detected by the liquid temperature sensor 202), and the wall temperature of the liquid reservoir 53 rises (detected by the wall temperature sensor 204).

Therefore, as shown in the control flow of the refrigerator in FIG. 8, the state of the gas in the reservoir 53 is determined in step 101, and when the gas temperature in the reservoir 53 rises, in step 102, Refrigerator 51
Increase the number of revolutions.

When the gas temperature in the liquid reservoir 53 decreases, in step 103, the rotation speed of the refrigerator 51 is reduced.

When there is no change in the gas temperature in the liquid reservoir 53, in step 104, the rotation of the refrigerator 51 is stopped.

In the cooling device according to the first embodiment having the above-described structure, the cooling liquid 54 such as liquid nitrogen in the liquid reservoir 53 of the shield plate cooling device 50 is pressurized by the pump 55 and passes through the pipe 58. The cryostat 1
When the gas flows into the pipe 101 in the
5 absorbs radiant heat entering the shield plate 103 and conduction heat transmitted through the support member 106 and evaporates itself, thereby keeping the temperature of the shield plate 103 substantially close to the temperature of the refrigerant liquid 54.

As a result, the container 112 filled with the refrigerant 104 such as liquid helium is directly placed in the vacuum tank 105.
From the heat. The refrigerant vapor flowing into the condenser 52 through the pipe 102 is supplied to the refrigerator 5
At 1, it is cooled and becomes a liquid, and returns to the liquid reservoir 53 again.

When the outside air temperature rises, the amount of heat entering the shield plate 103 increases, and the amount of evaporation of the refrigerant 54 such as liquid nitrogen increases. On the other hand, as a characteristic of the refrigerator, the refrigerating capacity increases as the temperature of the condensing section increases, so that the condensing temperature automatically increases to exhibit the refrigerating capacity commensurate with the amount of evaporation. Accordingly, the equilibrium pressure in the liquid reservoir 53 also increases,
The temperature of the refrigerant 53 stored in the liquid reservoir and the temperature of the shield plate 103 also increase.

That is, when the load on the shield plate is increased due to an increase in the outside air temperature, the pressure sensor 201 for measuring the pressure of the liquid reservoir 53, the liquid temperature sensor 202 for measuring the liquid temperature of the liquid reservoir 53, and the liquid reservoir 53 A gas temperature sensor 203 for measuring the gas temperature of 53, a wall temperature sensor 204 for measuring the wall temperature of the reservoir 52, a pipe for measuring the temperature of the pipes 101 and the pipes 101 and 102 in the cryostat 100. The temperature sensor 205 and the shield plate 10
3, a shield temperature sensor 206 for measuring the temperature of the condenser 52 of the refrigerator 51, a condenser temperature sensor 207 for measuring the temperature of the condenser 52 of the refrigerator 51, and the vacuum chamber 105 or the vacuum chamber 59.
The output of each sensor such as a vacuum chamber temperature sensor 208 for measuring the wall temperature of the vacuum chamber and an atmospheric temperature sensor 209 for measuring the ambient temperature around the vacuum chamber is caused.

Therefore, if at least one of the plurality of sensors detects the output, the increase or decrease in the heat load on the shield plate 103 can be determined, and the refrigerator control device 62 can be determined based on the determination result. The condensing temperature of the refrigerant 54 can be kept at a predetermined temperature because the control can increase or decrease the refrigerating capacity.

That is, the cooling device of the first embodiment controls the refrigerating capacity according to the increase or decrease in the heat load on the shield plate 103 regardless of the fluctuation of the atmospheric temperature in the four seasons.
In order to keep the condensing temperature of 4 at a predetermined temperature, the temperature of the refrigerant liquid such as liquid nitrogen can be kept within a predetermined temperature range, and the pressure of the refrigerant container can be prevented from abnormally rising and falling. This has the effect of eliminating the need for replenishment.

(First Modification of First Embodiment) A cooling device of a first modification of the first embodiment expands and contracts between the condensing section 52 and the liquid reservoir 53 as shown in FIG. Member 63
The difference from the first embodiment is that
The following description focuses on the differences. The same parts are denoted by the same reference numerals and their description is omitted.

The extendable member 63 is constituted by a bellows which is expandable and contractible and is formed in an airtight manner, and is provided at a connection portion between the casing of the liquid reservoir 53 and the condenser 52 of the refrigerator 51. The section 52 and the inside of the vacuum chamber 59 are partitioned.

In the cooling device according to the first modification of the first embodiment, the heat shrinkage at the time of low temperature is controlled by the expansion and contraction member 6 by the above configuration.
3, and prevents an excessive stress from being generated at a connection portion between the casing of the liquid reservoir 53 and the condenser 52 of the refrigerator 51, thereby providing an effect of preventing damage to the device.

(Second Modification of First Embodiment) As shown in FIG. 3, a cooling device of a second modification of the first embodiment includes a cooling unit of the refrigerator 51 and the vacuum chamber 59. The difference from the first embodiment is that the space is joined by an elastic member 64, and the following description will focus on the differences. The same parts are denoted by the same reference numerals and their description is omitted.

The extendable member 63 is constituted by a bellows which is expandable and contractible and is formed in an airtight manner, and is provided at a connection portion between the casing of the vacuum tank 59 and the room temperature section of the refrigerator 51. Partition the inside and outside of the building.

In the cooling device according to the second modification of the first embodiment, the heat shrinkage at the time of low temperature is controlled by the expansion member
4 to prevent an excessive stress from being generated in a connection portion between the casing of the vacuum chamber 59 and the normal temperature portion of the refrigerator 51, thereby providing an effect of preventing damage to the device.

(Third Modification of First Embodiment) A cooling device according to a third modification of the first embodiment includes a refrigerating machine 51 provided in a liquid reservoir 53 as shown in FIG. The difference from the first embodiment is that the condenser 52 is provided in both the low temperature part and the expansion part of the regenerator of the refrigerator 51.
The following description focuses on the differences. The same parts are denoted by the same reference numerals and their description is omitted.

The condenser 52 and the reservoir 5 formed in both the low temperature section and the expansion section of the regenerator of the refrigerator 51.
An expansion / contraction member 63 constituted by a bellows which is expandable and contractible and is formed in an airtight manner is disposed at a connection portion with the casing 3 to partition the condensing section 52 and the inside of the vacuum chamber 59.

In the cooling device according to the third modification of the first embodiment, the condensing portion 52 is formed in both the low-temperature portion and the expansion portion of the regenerator of the refrigerator 51 by the above configuration. Since the heat exchange area of the condensing section 52 can be increased, there is an effect that it is easier to control the temperature of the refrigerant liquid such as liquid nitrogen within a predetermined temperature range.

In the cooling device according to the third modification of the first embodiment, the heat shrinkage at low temperature is absorbed by the elastic member 63, and the casing of the reservoir 53 and the condenser 52 of the refrigerator 51 are absorbed.
This prevents an excessive stress from being generated at the connection portion with the connection member, thereby preventing the device from being damaged.

(Second Embodiment) The cooling device of the second embodiment is different from the cooling device of the second embodiment in that the refrigerator 51 and the condenser 52 are separated and independent from the shield plate cooling device 50 as shown in FIG. The following description focuses on the differences. The same parts are denoted by the same reference numerals and their description is omitted.

The refrigerator 51 and the condenser 52 separated and independent from the shield plate cooling device 50 are connected to a pipe 109.
Connected by

The condenser 52 is surrounded by a vacuum chamber 65. A pipe temperature sensor 205 for measuring the temperature of the pipe 102 and a condenser temperature sensor 207 for measuring the temperature of the condenser 52 of the refrigerator 51 are provided in the vacuum chamber 65.

The cooling device according to the second embodiment changes the arrangement of the components and has the same basic configuration, and thus has the same functions and effects as those of the first embodiment.

(Third Embodiment) In the cooling device of the third embodiment, as shown in FIG. 6, a cryostat 100 has a container 112 containing a superconducting magnet 107 and other objects to be cooled.
A shield plate 103 that covers the container 112, a pipe 101 through which a coolant that cools the shield plate 103 flows, and a liquid reservoir 53 that is located above the container 112 and stores a coolant 54 that cools the shield plate 103. And a refrigerator 51 which is engaged with the liquid reservoir 53 while keeping the airtight, a condenser 52 composed of a low-temperature part of the refrigerator 51, the liquid reservoir 53 and the pipe 1
It is composed of a pipe 58 connecting pipes 01, a pipe 102, and a vacuum tank 105 for accommodating them.

The refrigerator 51 is, for example, a Stirling refrigerator, and is driven by an inverter 61 and a control device 62 for controlling the inverter 61.

Further, a pressure sensor 201 for measuring the pressure of the reservoir 53, a liquid temperature sensor 202 for measuring the temperature of the reservoir 53, and a gas temperature sensor 203 for measuring the gas temperature of the reservoir 53 are provided. A wall temperature sensor 204 for measuring the wall temperature of the reservoir 53, a pipe temperature sensor 205 for measuring the temperatures of the pipe 58, the pipe 101, and the pipe 102;
A shield plate temperature sensor 206 for measuring the temperature of the shield plate 103; a condenser temperature sensor 207 for measuring the temperature of the condenser 52 of the refrigerator 51;
A plurality of necessary sensors are disposed among a vacuum chamber temperature sensor 208 for measuring the wall temperature of the vacuum chamber and an atmospheric temperature sensor 209 for measuring the ambient temperature around the vacuum chamber. Is done.

In the third embodiment having the above-described structure, the refrigerant 54 in the reservoir 53 is moved by gravity to the pipe 5.
8 and a pipe 101 for cooling the shield plate 103
Into the shield plate 103 by absorbing radiant heat that enters the shield plate 103 from the vacuum chamber 105 and conduction heat that enters through the support member 106 and evaporates itself.
The temperature of 3 is kept close to the temperature of the refrigerant liquid 54.

As a result, heat does not directly enter the container 112 filled with the refrigerant 104 such as liquid helium from the vacuum tank 105. The refrigerant vapor flowing into the condenser 52 through the pipe 102 is cooled by the refrigerator 51 to become a liquid, and returns to the liquid reservoir 53 again.

The cooling device according to the third embodiment has the same functions and effects as those of the first embodiment, and supplies the refrigerant liquid 54 for use by allowing the refrigerant liquid 54 to fall naturally using gravity. To eliminate the need for a pump
This has the effect of simplifying control and enabling cost reduction.

(Modification of Third Embodiment) A cooling device of a modification of the third embodiment has a refrigerator 5 as shown in FIG.
1 from the cryostat 100 and the refrigerator 5
1 is that the condenser 52 composed of the low-temperature section is disposed above the liquid reservoir 53, and the condenser 52 and the liquid reservoir 53 are connected by a pipe 66 and a pipe 67. , And the same parts will be denoted by the same reference numerals and description thereof will be omitted.

According to this modification, the shield plate 103
The refrigerant gas that has cooled the reservoir 5
Return to 3. The refrigerant gas in the sump flows into the condenser 52 through the pipe 66, and the liquefied refrigerant is supplied to the pipe 6
7 and return to the reservoir 53.

This modified example has the same operation and effect as the above-described first embodiment, and uses the refrigerant liquid 54 by allowing the refrigerant liquid 54 to fall naturally by using gravity as in the third embodiment. Since a pump for supplying the liquid 54 is not required, there is an effect that the control is simplified and the cost can be reduced.

The above-described embodiments have been described by way of example only, and the present invention is not limited to these embodiments. Those skilled in the art will recognize from the claims, the detailed description of the invention, and the drawings. Modifications and additions are possible without departing from the technical idea of the present invention.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a first modification of the first embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a second modification of the first embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a device according to a third modification of the first embodiment of the present invention.

FIG. 5 is a sectional view showing a device according to a second embodiment of the present invention and a conventional device.

FIG. 6 is a sectional view showing a device according to a third embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating a modification of the third embodiment.

FIG. 8 is a chart showing a control flow of the rotation speed of the refrigerator in each embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 50 cooling device 51 refrigerator 52 condenser 53 liquid reservoir 103 shield plate 107 object to be cooled 112 container

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hideo Misawa 2-1-1 Asahi-cho, Kariya-shi, Aichi Prefecture Inside Aisin Seiki Co., Ltd. (72) Inventor Takashi Mitsumoto 2-1-1 Asahi-cho, Kariya-shi, Aichi Prefecture Aishi (72) Inventor Toshiyuki Amano 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 4M114 AA02 AA31 BB01 BB04 CC03 CC13 CC16 CC18 DA02 DA07 DA09 DA10 DA12 DA32 DA45 DA47

Claims (12)

[Claims] 1. A cooling device for cooling a cooled object such as a superconducting magnet or a shield plate covering around a container containing the cooled object, wherein a refrigerant for cooling the shield plate is accommodated, A cooling device for controlling the number of revolutions of the refrigerator in accordance with a state of gas in a liquid reservoir provided with a condensing portion of the refrigerant constituted by a low-temperature portion of the refrigerator. 2. The apparatus according to claim 1, further comprising a pressure sensor for detecting a pressure of the gas in the liquid reservoir, and controlling a rotation speed of the refrigerator according to the detected pressure of the gas in the liquid reservoir. Characterized cooling device. 3. The apparatus according to claim 2, further comprising a gas temperature sensor for detecting a temperature of the gas in the liquid reservoir, and controlling a rotation speed of the refrigerator according to the detected temperature of the gas in the liquid reservoir. A cooling device characterized by the following. 4. The cooling system according to claim 3, further comprising a shield plate temperature sensor for detecting a temperature of the shield plate, wherein a rotation speed of the refrigerator is controlled in accordance with the detected temperature of the shield plate. apparatus. 5. The liquid storage device according to claim 4, further comprising a liquid temperature sensor for detecting a liquid temperature in the liquid reservoir, and controlling a rotation speed of the refrigerator in accordance with the detected liquid temperature in the liquid reservoir. And cooling device. 6. The refrigerator according to claim 5, further comprising a condenser temperature sensor for detecting a temperature of the condenser of the refrigerator, and controlling a rotation speed of the refrigerator according to the detected temperature of the condenser of the refrigerator. A cooling device characterized by the above. 7. The apparatus according to claim 6, further comprising a vacuum chamber temperature sensor for detecting a temperature of a vacuum chamber containing the container, and controlling a rotation speed of the refrigerator according to the detected temperature of the vacuum chamber. Characterized cooling device. 8. The air conditioner according to claim 7, further comprising an air temperature sensor for detecting an air temperature around the vacuum chamber, and controlling a rotation speed of the refrigerator according to the detected air temperature around the vacuum chamber. A cooling device characterized by the following. 9. A cooled object or a container accommodating the cooled object, a shield plate covering the cooled object or the container, a pipe through which a refrigerant for cooling the shield plate flows, the cooled object or the container A cryostat composed of a vacuum tank for accommodating the shield plate and the pipe, a liquid reservoir containing the refrigerant, a pump for sending the refrigerant from the liquid reservoir, and a pipe through which the refrigerant sent from the pump flows A shield plate cooling device composed of a vacuum tank containing the liquid reservoir, the pump, and the piping; and a low-temperature device composed of piping connecting the cryostat and the shield plate cooling device. Providing a condenser for condensing the refrigerant composed of a low-temperature part, the pressure of the liquid reservoir, the liquid temperature of the liquid reservoir, the gas temperature of the liquid reservoir, the wall temperature of the liquid reservoir, the temperature of the piping, At least one sensor output among a temperature of a metal plate, a temperature of a condensing part of the refrigerator, a temperature of the vacuum chamber, and an atmospheric temperature around the vacuum chamber, and detects the output of the refrigerator in accordance with the detected sensor output. A cooling device characterized by controlling the number of rotations of a cooling device. 10. The cooling device according to claim 9, wherein the liquid reservoir and the condenser of the refrigerator are connected by a telescopic member. 11. The refrigerator according to claim 9, wherein a condensing portion for the refrigerant, which is formed by a low-temperature portion of the refrigerator, is provided in the liquid reservoir, and a normal-temperature portion of the refrigerator and the vacuum chamber are connected by a telescopic member. A cooling device, characterized in that: 12. The cooling device according to claim 9, wherein the refrigerator is a regenerative refrigerator, and a condenser is provided in both a low-temperature part of the regenerator and a low-temperature part of the expansion part of the refrigerator. .